Polycarbonate has good mechanical properties such as tensile strength, impact resistance, etc. and also has good dimensional stability, heat resistance and optical transparency. Thus, it has been extensively used in many industries. However, although polycarbonate has good impact resistance at room temperature, its impact resistance rapidly becomes worse at low temperature.
To improve such a disadvantage, various copolymers have been researched and it has been known that polysiloxane-polycarbonate copolymer has relatively good impact resistance at low temperature. However, polysiloxane-polycarbonate copolymers that are currently used conventionally require a high amount of siloxane to show low-temperature impact resistance, and thus the manufacturing costs are inevitably increased. In addition, they have a problem of deterioration in flowability and moldability due to increase of the molecular weight of the copolymer.
Accordingly, there is a need to develop a polysiloxane-polycarbonate copolymer which can exhibit excellent low-temperature impact resistance even with low siloxane content, while having improved flowability and moldability.